Improvement of cryogenic fluid storage and transfer technology for in-space propulsion and storage systems is required for the longterm development of cislunar space. Current technology relies on…

The National Aeronautics and Space Administration (NASA) awarded a $489,527.18 grant to Southwest Research Institute, a nonprofit research organization, for a project to improve cryogenic fluid storage and transfer technology for in-space propulsion and storage systems. The goal is to further develop a tapered liquid acquisition device design that can passively remove vapor bubbles to reliably deliver cryogenic fluids, building on previous ground and microgravity testing. This research supports NASA's long-term development of cislunar space capabilities. The contract does not have a small business set-aside designation.

Improvement of cryogenic fluid storage and transfer technology for in-space propulsion and storage systems is required for the longterm development of cislunar space. Current technology relies on the capillary force within screened channels of a liquid acquisition device (LAD) to deliver vapor-free cryogenic liquid during engine restart and critical transfer processes. However, due to the low temperatures associated with cryogenic fluids, external heating acting on the tank where this fluid is stored will cause vapor bubbles to form within the LAD that are difficult to remove in existing designs. A more efficient design is needed to reliably remove vapor bubbles without costly thrusting maneuvers or active separation systems. A small modification to a commonly used LAD is proposed: a tapered channel. This design passively removes or pumps-out cryogenic vapor bubbles that are internally generated using surface tension forces, substantially improving transfer or delivery of cryogenic fluids. The goal of this project is to utilize the experience gained in ground tests and a previous suborbital microgravity test of small-scale tapered lads to further develop the technology at larger scale in a relevant microgravity environment. The test apparatus will include large-scale tapered screen channels filled with liquid and a gas bubble. A camera will record gas bubble migration under various accelerations including long-duration microgravity. These data will be used to further validate the concept and improve models for designing tapered lads.